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Inside Natures Prehistoric Giants: “Livyatan”, the Killer Sperm Whale

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The jagged southern coastline of Australia, 5.5 million years ago...   Modern Sperm whales are the largest toothed animals that have ever existed. At 20 metres in length and over 50 metric tonnes, "Physeter" and its distant relatives have dominated the marine landscape since the Pliocene... Image via Caters News Agency The Miocene climate in Australia is significantly warmer. The vegetation is slowly transitioning on the mainland; where once lush rainforests adorned the isolated continent throughout the Oligocene and mid Miocene, dry schlerophyll forests and open woodland are dominating the landscape with stringy barked eucalypts. Bizarre creatures traverse these coastlines; Zygomaturines (cow sized animals that superficially resemble wombats) stomp over small shrubby vegetation, the so-called “Demon Ducks of Doom” (2 metre tall flightless birds) race each other, kicking up the dust behind them and giant flying sea-birds (the Pelagornithids, with a 6
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The Evolutionary Dead-End Experiments of Crocodiles

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It was at this moment that Steve the fish realised he had made a dire mistake (Image via Andy Murch) Crocodiles are NOT living fossils...  They may look ancient, with a smattering of characteristics that make them look like non-avian dinosaurs, but as we dive back throughout the Mesozoic and come up for air in the murky waters of the late Triassic (roughly 230 million years ago), we find that the distant ancestors of the creatures we refer to as the heavily armored   “ Crocodylia ” (a group that includes all “true” crocodiles, caimans, alligators and gharials) look so completely different from their modern counterparts. Many early crocodylimorphs (a term that is used to include modern and long-extinct cousins of crocodilians) were completely terrestrial and include the ~230 million year old “ Trialestes ”, an animal that was originally interpreted as a basal dinosaur, due to its “un-crocodilian” upright stance. Thanks to the fossil record, we have an
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